ADVANCED DRAINAGE SYSTEMS, INC.

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

(UNAUDITED)

1. BACKGROUND AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Description of Business- Advanced Drainage Systems, Inc., incorporated in Delaware, and its subsidiaries (collectively referred to as “ADS” or the “Company”) designs, manufactures and markets innovative water management solutions in the stormwater and onsite septic wastewater industries, providing superior drainage solutions for use in the construction and agriculture marketplace. ADS’s products are used across a broad range of end markets and applications, including non-residential, residential, infrastructure and agriculture applications.

The Company is managed and reports results of operations inthree reportable segments: Pipe, Infiltrator Water Technologies, LLC (“Infiltrator”) and International. The Company also reports the results of its Allied Products and all other business segments as Allied Products & Other.

Historically, sales of the Company’s products have been higher in the first and second quarters of each fiscal year due to favorable weather and longer daylight conditions accelerating construction activity during these periods. Seasonal variations in operating results may also be impacted by inclement weather conditions, such as cold or wet weather, which can delay projects.

Basis of Presentation- The Company prepares its Condensed Consolidated Financial Statements in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The Condensed Consolidated Balance Sheet as of March 31, 2025 was derived from audited financial statements included in the Annual Report on Form 10-K for the year ended March 31, 2025 (“Fiscal 2025 Form 10-K”). The accompanying unaudited Condensed Consolidated Financial Statements contain all adjustments, of a normal recurring nature, necessary to present fairly its financial position as of December 31, 2025, the results of operations for the three and nine months ended December 31, 2025 and cash flows for the nine months ended December 31, 2025. The interim Condensed Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements, including the notes thereto, filed in the Company’s Fiscal 2025 Form 10-K.

Presentation- Prior period segment results and related disclosures have been recast to conform to the current period segment presentation. See “Note 13. Business Segment Information” for additional information.

Principles of Consolidation- The Condensed Consolidated Financial Statements include the Company, its wholly-owned subsidiaries, its majority-owned subsidiaries and variable interest entities of which the Company is the primary beneficiary. The Company uses the equity method of accounting for equity investments where it exercises significant influence but does not hold a controlling financial interest. Such investments are recorded in Other assets in the Condensed Consolidated Balance Sheets and the related equity earnings from these investments are included in Equity in net income of unconsolidated affiliates in the Condensed Consolidated Statements of Operations. All intercompany balances and transactions have been eliminated in consolidation.

Recent Accounting Guidance

Measurement of Credit Losses for Accounts Receivable and Contract Assets- In July 2025, the FASB issued an accounting standards update (“ASU”) which amends Accounting Standards Codification (“ASC”) 326-20 to provide a practical expedient and an accounting policy election related to the estimation of expected credit losses for current accounts receivable and current contract assets that arise from transactions accounted for under ASC 606. An entity is required to disclose whether it has elected to use the practical expedient and, if so, whether it has also applied the accounting policy election. The ASU is effective for fiscal years beginning after December 15, 2025, and interim reporting periods within those annual reporting periods, with early adoption permitted. The new guidance is to be applied prospectively. The Company is currently evaluating the impact this standard will have on the Condensed Consolidated Financial Statements.

Accounting for and Disclosure of Software Costs - In September 2025, the FASB issued an ASU which amends certain aspects of ASC 350-40. The amended guidance eliminates project stages and requires capitalizing software costs to begin when (1) management has authorized and committed to funding the software project and (2) it is probable that the project will be completed and the software will be used to perform the function intended. When evaluating if a project is probable to be completed, significant development uncertainty must be assessed. Additionally, disclosures for property, plant and equipment will be required for all capitalized software costs. The ASU is effective for fiscal years beginning after December 15, 2027, and interim reporting periods within those annual reporting periods, with early adoption permitted. The Company is currently evaluating the impact this standard will have on the Condensed Consolidated Financial Statements.

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Except for the pronouncements described above, there have been no new accounting pronouncements issued or adopted since the filing of the Fiscal 2025 Form 10-K that have significance, or potential significance, to the Consolidated Financial Statements.

2. RESTRUCTURING AND LOSS (GAIN) ON DISPOSAL OF ASSETS AND COSTS FROM EXIT AND DISPOSAL ACTIVITIES

In fiscal 2026, the Company undertook certain restructuring and realignment activities (the “2026 Restructuring Plan”) to optimize the Company’s production, recycling and distribution network. Under the 2026 Restructuring Plan, during the three and nine months ended December 31, 2025, the Company recorded expense of $1.7 million and $17.7 million, respectively, related to the closure of one of the Company’s recycling facilities to optimize its recycling network, one offsite storage location and one distribution yard. The Company does not currently have an estimate of additional costs or an expected end date for the restructuring actions. The following table summarizes the activities included in Restructuring and realignment expense during the periods presented.

The costs incurred under the 2026 Restructuring Plan to date are classified as operating expenses and not allocated to a segment. During the three and nine months ended December 31, 2025, the Company recorded accelerated depreciation, severance costs, impairment of right-of-use lease assets and other exit and disposal costs. Other exit and disposal activities include legal and professional fees, inventory and equipment transfer costs and other costs.

The following table summarizes the restructuring liability for the periods presented:

The restructuring liability is recorded in Other accrued liabilities in the Company’s Condensed Consolidated Balance Sheet.

Loss (Gain) on Disposal of Assets and Costs From Exit and Disposal Activities - The Company recorded a less than $0.1 million loss and a $16.4 million gain on disposal of assets in the three and nine months ended December 31, 2025, respectively. The sale of properties previously held-for-sale resulted in the gain of $18.1 million. The remaining balance is due to the sale or disposal of other property, plant and equipment.

3. ACQUISITIONS

Acquisition of Orenco -On October 1, 2024, the Company’s wholly-owned subsidiary, Infiltrator, completed the acquisition of Orenco Systems, Inc. (“Orenco”), a leading manufacturer of decentralized wastewater management products serving residential and non-residential end markets. The fair value of consideration transferred was approximately $236.3 million, which represented the purchase price of $255.0 million, net of cash acquired of $18.7 million. The purchase price excludes transactions costs. The acquisition was funded from cash on hand. Orenco will be included in the Infiltrator reportable segment.

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The following table summarizes the consideration transferred and the purchase price allocation of assets acquired and liabilities assumed:

The goodwill of $104.2 million represents the excess of consideration transferred over the fair value of assets acquired and liabilities assumed and is attributable to expected operating efficiencies. The goodwill is not deductible for income tax purposes and is assigned to Infiltrator.

Acquisition of River Valley Pipe -On May 8, 2025, the Company completed its acquisition of the assets of River Valley Pipe LLC (“River Valley Pipe”), a privately-owned pipe manufacturing company located in the Midwest region of the United States. The preliminary fair value of consideration transferred was approximately $18.8 million. The acquisition was funded from cash on hand. River Valley Pipe is included in the Pipe reportable segment.

The following table summarizes the consideration transferred and the preliminary purchase price allocation of assets acquired and liabilities assumed. The purchase price allocation for assets acquired and liabilities assumed is preliminary and will be finalized when valuations are complete and final assessments of the fair value of acquired assets and assumed liabilities are completed. Such finalization may result in material changes from the preliminary purchase price allocation. The Company's estimates and assumptions are subject to change during the measurement period (up to one year from the closing date), as the Company continues to finalize the valuations of assets acquired and liabilities assumed.

The preliminary goodwill of $3.9 million represents the excess of consideration transferred over the preliminary fair value of assets acquired and liabilities assumed and is attributable to expected operating efficiencies. The goodwill is deductible for income tax purposes and is assigned to Pipe.

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The preliminary purchase price excludes transaction costs. During the nine months ended December 31, 2025, the Company incurred $0.5 million of transaction costs related to the acquisition such as legal, accounting, valuation and other professional services. These costs are included in selling, general and administrative expenses in the Condensed Consolidated Statements of Operations and Condensed Consolidated Statements of Comprehensive Income.

The identifiable intangible assets recorded in connection with the acquisition of River Valley Pipe are based on preliminary valuations including customer relationships and tradename totaling $3.0 million. The intangible assets will be amortized on a straight-line basis over their estimated useful lives.

The Company has excluded certain disclosures required under ASC 805, Business Combinations as they are not material to the financial statements.

4. REVENUE RECOGNITION

Revenue Disaggregation - The Company disaggregates net sales by Domestic, International and Infiltrator and further disaggregates Domestic and International by product type, consistent with its reportable segment disclosure. This disaggregation level best depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. Refer to “Note 13. Business Segment Information” for the Company’s disaggregation of Net sales by reportable segment. The following table presents net sales (including intersegment net sales) disaggregated by product type for the Company’s International segment.

Contract Balances -The Company recognizes a contract asset representing the Company’s right to recover products upon the receipt of returned products and a contract liability for the customer refund. The following table presents the balance of the Company’s contract asset and liability as of the periods presented:

5. LEASES

Nature of the Company’s Leases - The Company has operating and finance leases for plants, yards, corporate offices, tractors, trailers and other equipment. The Company’s leases have remaining terms of less thanone year to 11 years. A portion of the Company’s yard leases include an option to extend the leases for up tofive years. The Company has included renewal options which are reasonably certain to be exercised in its right-of-use assets and lease liabilities.

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6. INVENTORIES

Inventories as of the periods presented consisted of the following:

7. NET INCOME PER SHARE AND STOCKHOLDERS' EQUITY

Net Income per Share - The following table presents information necessary to calculate net income per share for the periods presented, as well as potentially dilutive securities excluded from the weighted average number of diluted common shares outstanding because their inclusion would have been anti-dilutive:

8. RELATED PARTY TRANSACTIONS

ADS Mexicana- ADS conducts business in Mexico and Central America through its joint venture, ADS Mexicana, S.A. de C.V. (“ADS Mexicana”). ADS owns 51% of the outstanding stock of ADS Mexicana and consolidates ADS Mexicana for financial reporting purposes.

On June 6, 2022, the Company and ADS Mexicana amended the Intercompany Revolving Credit Promissory Note (the “Intercompany Note”) with a borrowing capacity of $9.5 million. The Intercompany Note matures on June 8, 2027. The Intercompany Note indemnifies the ADS Mexicana joint venture partner for 49% of any unpaid borrowings. The interest rates under the Intercompany Note are determined by certain base rates or Secured Overnight Financing Rate (“SOFR”) plus an applicable margin based on the Leverage Ratio. As of both December 31, 2025 and March 31, 2025, there wereno borrowings outstanding under the Intercompany Note.

South American Joint Venture- The Tuberias Tigre - ADS Limitada joint venture (the “South American Joint Venture”) manufactures and sells HDPE corrugated pipe in certain South American markets. ADS owns 50% of the South American Joint Venture. ADS is the guarantor of 50% of the South American Joint Venture’s credit arrangement, and the debt guarantee is shared equally with the joint venture partner. The Company’s maximum potential obligation under this guarantee is $5.5 million as of December 31, 2025. The maximum borrowings permitted under the South American Joint Venture’s credit facility are $11.0 million. The Company does not anticipate any required contributions related to the balance of this credit arrangement. As of December 31, 2025 and March 31, 2025, there wasno outstanding principal balance for the South American Joint Venture’s credit facility, including letters of credit.

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9. DEBT

Long-term debt as of the periods presented consisted of the following:

Senior Secured Credit Facility- In May 2022, the Company entered into a Second Amendment (the “Second Amendment”) to the Company's Base Credit Agreement with Barclays Bank PLC, as administrative agent under the Term Loan Facility and PNC Bank, National Association, as new administrative agent under the Revolving Credit Facility. Among other things, the Second Amendment (i) amended the Base Credit Agreement by increasing the Revolving Credit Facility (the “Amended Revolving Credit Facility”) from $350 million to $600 million (including an increase of the sub-limit for the swing-line sub-facility from $50 million to $60 million), (ii) extended the maturity date of the Revolving Credit Facility to May 26, 2027, (iii) revised the “applicable margin” to provide an additional step-down to 175 basis points (for Term Benchmark based loans) and 75 basis points (for base rate loans) in the event the consolidated senior secured net leverage ratio is less than 2.00 to 1.00, and (iv) reset the “incremental amount” and the investment basket in non-guarantors and joint ventures. The Second Amendment also revised the reference interest rate from LIBOR to SOFR for both the Amended Revolving Credit Facility and the Term Loan Facility. On November 26, 2025, the Company entered into a Third Amendment to the Company’s Base Credit Agreement modifying the termination date for the Amended Revolving Credit Facility. Letters of credit outstanding at December 31, 2025 and March 31, 2025 amounted to $10.1 million and $9.5 million, respectively, and reduced the availability of the Revolving Credit Facility.

The maturity date of the Term Loan Facility is September 24, 2026. As of December 31, 2025, the Company has continued to classify the Term Loan Facility as long-term debt as the Company has the intent and the ability to refinance these borrowings on a long-term basis as supported by the available capacity under the Revolving Credit Facility.

Senior Notes due 2027- On September 23, 2019, the Company issued $350.0 million aggregate principal amount of 5.0% Senior Notes due 2027 (the “2027 Notes”) pursuant to an Indenture, dated September 23, 2019 (the “2027 Indenture”), among the Company, the guarantors party thereto (the “Guarantors”) and U.S. Bank National Association, as Trustee (the “Trustee”).

Senior Notes due 2030- On June 9, 2022, the Company issued $500.0 million aggregate principal amount of 6.375% Senior Notes due 2030 (the “2030 Notes”) pursuant to an Indenture, dated June 9, 2022 (the “2030 Indenture”), among the Company, the Guarantors and the Trustee.

Other debt-Other debt includes equipment financing and the commercial loan related to the Company’s headquarters. The assets under the Equipment Financing acquired are titled to the Company and included in Property, plant and equipment, net on the Company's Condensed Consolidated Balance Sheet. The equipment financing has an initial term of between 12 and 84 months, based on the life of the equipment, and bears a weighted average interest rate of 1.8%as of December 31, 2025. The current portion of the equipment financing is $1.2 million, and the long-term portion is $2.2 million at December 31, 2025.

The Company entered into a commercial loan agreement of $27.2 million which matures on December 5, 2028. The agreement bears interest based on SOFR plus a margin of 285 basis points, requires interest only payments through December 5, 2026, and beginning January 5, 2027 through maturity, includes principal and interest payments. As of December 31, 2025, the loan balance is classified as long-term debt in the Condensed Consolidated Balance Sheet.

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Valuation of Debt -The carrying amounts of current financial assets and liabilities approximate fair value because of the immediate or short-term maturity of these items. The following table presents the carrying and fair value of the Company’s 2027 Notes, 2030 Notes and Equipment Financing for the periods presented:

The fair values of the 2027 Notes and 2030 Notes were determined based on quoted market data for the Company’s 2027 Notes and 2030 Notes, respectively. The fair value of the Equipment Financing was determined based on a comparison of the interest rate and terms of such borrowings to the rates and terms of similar debt available for the period. The categorization of the framework used to evaluate the 2027 Notes, 2030 Notes and Equipment Financing are considered Level 2. The Company believes the carrying amount of the remaining long-term debt, including the Term Loan Facility, Revolving Credit Facility and Commercial loan agreement, is not materially different from its fair value as the interest rates and terms of the borrowings are similar to currently available borrowings.

10. COMMITMENTS AND CONTINGENCIES

Purchase Commitments- The Company has historically secured supplies of resin raw material by agreeing to purchase quantities during a future given period at a fixed price. These purchase contracts typically ranged from 1 to 12 months and occur in the ordinary course of business. The Company doesnot have any outstanding purchase commitments with fixed price and quantity as of December 31, 2025. The Company also enters into equipment purchase contracts with manufacturers.

Litigation and Other Proceedings- The Company is involved from time to time in various legal proceedings that arise in the ordinary course of business, including but not limited to commercial disputes, environmental matters, employee related claims, intellectual property disputes and litigation in connection with transactions including acquisitions and divestitures. The Company does not believe that such litigation, claims, and administrative proceedings will have a material adverse impact on the Company’s financial position or results of operations. The Company records a liability when a loss is considered probable, and the amount can be reasonably estimated.

11. INCOME TAXES

The Company’s effective tax rate will vary based on a variety of factors, including overall profitability, the geographical mix of income before taxes and related tax rates in jurisdictions where it operates and other one-time charges, as well as the occurrence of discrete events. For the three months ended December 31, 2025 and 2024, the Company utilized an effective tax rate of 24.9% and 25.0%, respectively, to calculate its provision for income taxes. For the nine months ended December 31, 2025 and 2024, the Company utilized an effective tax rate of 24.9% and 24.0%, respectively, to calculate its provision for income taxes. State and local income taxes increased the effective rate for the three and nine months ended December 31, 2025 and 2024.

12. STOCK-BASED COMPENSATION

ADS has several programs for stock-based payments to employees and non-employee members of its Board of Directors, including stock options, performance-based restricted stock units and restricted stock. The Company recognized stock-based compensation expense in the following line items of the Condensed Consolidated Statements of Operations for the periods presented:

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The following table summarizes stock-based compensation expense by award type for the periods presented:

2017 Omnibus Incentive Plan- The 2017 Incentive Plan provides for the issuance of a maximum of 5.0 million shares of the Company’s common stock for awards made thereunder, which awards may consist of stock options, restricted stock, restricted stock units, stock appreciation rights, phantom stock, cash-based awards, performance awards (which may take the form of performance cash, performance units or performance shares) or other stock-based awards.

Restricted Stock-During the nine months ended December 31, 2025, the Company granted 0.1 million shares of restricted stock with a grant date fair value of $13.9 million.

Performance-based Restricted Stock Units (“Performance Units”)-During the nine months ended December 31, 2025, the Company granted 0.1 million shares of performance units at a grant date fair value of $14.3 million.

Options- During the nine months ended December 31, 2025, the Company granted 0.1 million nonqualified stock options under the 2017 Incentive Plan with a grant date fair value of $7.5 million. The Company estimates the fair value of stock options using a Black-Scholes option-pricing model. The following table summarizes the assumptions used to estimate the fair value of stock-options during the period presented:

Employee Stock Purchase Plan (“ESPP”) -In July 2022, the Company’s stockholders approved the Advanced Drainage Systems, Inc. Employee Stock Purchase Plan, which provides for a maximum of 0.4 million shares of the Company’s common stock. Eligible employees may purchase the Company's common stock at 85% of the lower of the fair market value of the Company's common stock on the first day or the last day of the offering period. The offering periods are six months in duration beginning either January 1 or July 1 and ending June 30 and December 31.

13. BUSINESS SEGMENT INFORMATION

The Company operates its business inthree distinct reportable segments: “Pipe”, “International” and “Infiltrator.” “Allied Products & Other” represents the Company’s Allied Products and all other business segments. The Chief Operating Decision Maker (“CODM”) for ADS is the Chief Executive Officer (“CEO”). The CEO reviews financial information and makes operational decisions based on Net sales and a measure of operating profit, Segment Adjusted Gross Profit. A measure of assets is not applicable, as segment assets are not regularly reviewed by the CODM for evaluating performance or allocating resources.

In the first quarter of fiscal 2026, the Company realigned certain products used in wastewater applications to the Infiltrator reportable segment. The Company transitioned its ARC Septic Chambers from Allied Products & Other and certain pipe products used in wastewater applications from Pipe. Prior period segment information for fiscal 2025 has been recast to conform to the fiscal 2026 presentation.

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The following table sets forth reportable segment information with respect to the amount of Net sales contributed by each class of similar products for the periods presented:

Reconciliation of Gross Profit to Segment Adjusted Gross Profit - The Company calculates Segment Adjusted Gross Profit as Net sales less costs of goods sold excluding depreciation and amortization, stock-based compensation and certain other expenses. The following table reconciles the Segment Adjusted Gross Profit to Gross Profit:

Significant Segment Expenses - The Company has identified Cost of Goods Sold as a significant expense category. The following tables set forth reportable segment information with respect to significant segment expenses and the

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(a) Depreciation, Amortization and Other are included to reconcile to Adjusted Gross Profit and include Depreciation and Amortization, Stock-based compensation expense and Inventory step-up related to Orenco acquisition.

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The following sets forth certain financial information attributable to the reportable segments for the periods presented:

(a)Includes depreciation and amortization in both Cost of goods sold and Operating expenses.

(b)Includes depreciation, amortization and capital expenditures not allocated to a reportable segment. The amortization expense of Infiltrator intangible assets is included in Allied Products & Other.

14. SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION

Supplemental disclosures of cash flow information for the nine months ended December 31, were as follows:

15. SUBSEQUENT EVENTS

Common Stock Dividend - Subsequent to the end of the quarter, the Company declared a quarterly cash dividend of $0.18 per share of common stock. The dividend is payable on March 16, 2026, to stockholders of record at the close of business on March 2, 2026.

Acquisition of National Diversified Sales (“NDS”) - On February 2, 2026, the Company completed its previously announced acquisition of the outstanding capital stock of certain indirect subsidiaries of NORMA Group SE, which comprise substantially all of Norma Group’s water management business known as NDS, subject to the terms and conditions set forth in the Master Share Purchase Agreement dated September 23, 2025. The acquisition is an all cash transaction for consideration of approximately $1.0 billion, subject to certain purchase price adjustments.

Share Repurchase Program - In February 2026, the Company announced that the Board approved a new $1.0 billion stock repurchase authorization (the “Repurchase Program”) of ADS common stock in accordance with applicable securities laws. With the new authorization, the Repurchase Program has available capacity of $1.1 billion. The repurchase program does not obligate the Company to acquire any particular amount of common stock and may be suspended or terminated at any time at the Company’s discretion.

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